Most general chemistry laboratory manuals include coffee-cup calorimeters experiments for the determination of enthalpy of reactions (for example, acid-base neutralization) under constant pressure conditions. Although all general chemistry textbooks include a discussion of bomb calorimetry to evaluate the enthalpy of combustion reactions under constant volume conditions, these experiments are uncommon in the laboratory manuals. Exposing students to constant pressure AND constant volume calorimetry provides a more wholesome educational experience in the general chemistry laboratory, especially since these students are expected to solve problems from each of these techniques. In this presentation I will discuss an experiment where bomb calorimetry was used in the general chemistry laboratory to evaluate the economic viability of coal samples. Students worked in small teams to evaluate the enthalpy of combustion of one of five available coal samples. The raw data from each team were then shared, so each student could analyze the entire class data set using spreadsheet (Microsoft Excel) software. Students used their analysis to grade the coals samples for their economic viability based on their enthalpies of combustion. Students received instruction on the formation of various coal samples under different geologic conditions. Transferable skills learned during this experiment included using Vernier probes and Logger Pro software for data collection as well as graphing and data analysis with spreadsheet software. This laboratory was first designed for a course that integrated general chemistry with physical and environmental geology (first-year college students). However, it has been repeatedly used since in the regular general chemistry laboratory sequence. The experiment has also been modified and used in the physical chemistry laboratory. Experiences from teaching this laboratory with each of these student groups will be discussed during the presentation.

Evaluating the economic viability of coal samples using bomb calorimetry: A problem based, interdisciplinary laboratory exercise for general chemistry students

2019 Spring National Meeting

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